1. Field of the Invention
The present invention relates to sensor alignment methods and systems, and more particularly to a radar alignment and verification method and system for aligning or verifying the alignment of a radar antenna array attached to an automobile.
2. Description of the Related Art
Sensors, such as radar antenna arrays, are used on automobiles to provide drivers with features such as blind-spot detection, parking aids, adaptive cruise control, pre-crash sensing, and the like. The sensors are attached at various locations on the automobile and generate a plurality of directional beams that provide information regarding objects located in the vicinity of the automobile.
The beams of a sensor must be radiated at a predetermined azimuthal angle to provide accurate information. Furthermore, depending on the beam pattern of the sensor, a predetermined elevation angle may also be required. Accordingly, the sensor is usually installed on a mounting bracket that facilitates azimuthal angle and elevation angle adjustment. During installation of the sensor, the sensor alignment must be verified. Furthermore, at certain times during the life of the automobile, such as a scheduled maintenance routine, the sensor alignment must again be verified. Additionally, if the sensor is out of alignment, the sensor must be adjusted and brought back into alignment.
A novel method of aligning a sensor device attached to an automobile comprises the steps of positioning a first detection object relative to the automobile and generating a plurality of beams at the sensor device. A beam crossing point common to first and second adjacent beams is selected, and the sensor alignment is verified by determining whether the beam crossing point is coincident with the first detection object.
Another novel method of aligning a sensor device attached to an automobile comprises the steps of defining a sensor axis and positioning first and second detection objects relative to the automobile. The first detection object is coincident with the sensor axis, and the second detection object is vertically displaced from the sensor axis. A plurality of beams is generated, and first and second signal levels are determined in first and second beams, respectively. The first signal level corresponds to the first detection object, and the second signal level corresponds to the second detection object. Sensor alignment is determined based on the first and second signal levels.
A novel system for aligning a sensor device attached to an assembly comprises a first positioning fixture operable to place the assembly in a first location, and a second positioning fixture operable to place a first detection object in a second location. The second location is relative to the assembly such that the first detection object is positioned at a beam crossing point of first and second adjacent beams when the sensor device is aligned.